Pulmonary arteriovenous fistula

Definition

Pulmonary arteriovenous fistula is an abnormal connection between an artery and vein in the lungs. As a result, blood passes through the lungs without receiving enough oxygen.

Alternative Names

Arteriovenous malformation - pulmonary

Causes

Pulmonary arteriovenous fistulas are usually the result of abnormal development of the blood vessels of the lung. Most occur in patients with Rendu-Osler-Weber disease (ROWD) – now commonly called hereditary hemorrhagic telangiectasia (HHT). These patients often have abnormal blood vessels in many parts of the body, including the lung.

Fistulas also can be a complication of liver disease or lung injury, although this is much less common.

Treatment

A small number of patients who have no symptoms may not need treatment. For most patients with fistulas, the treatment of choice is to block the fistula during an arteriogram (embolization).

Some patients may need surgery to remove the abnormal vessels and nearby lung tissue.

When arteriovenous fistulas are caused by liver disease, the treatment is a liver transplant.

Outlook (Prognosis)

The outlook for patients with HHT is not as good as for those without HHT. For patients without HHT, surgery to remove the abnormal vessels usually has a good outcome, and the condition is not likely to return.

Possible Complications

Major complications after treatment for this condition are unusual. Complications may include:

Bleeding in the lung

Stroke due to blood clot that travels from the lungs to the arms, legs, or brain (paradoxical venous embolism)

Infection in the brain or heart valve, especially in patients with HHT

When to Contact a Medical Professional

Call your health care provider if you often have nosebleeds or difficulty breathing, especially if you also have a personal or family history of HHT.

Prevention

Because this condition is often genetic, prevention is not usually possible.